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伯胺N1923萃取钯(Ⅱ)的动力学研究 总被引:1,自引:0,他引:1
有关伯胺萃取钯(Ⅱ)的动力学研究,尚未见报道。本文用恒界面池搅拌法考察了N1923-正辛烷溶液从氯化物介质中萃取Pd(Ⅱ)时,诸因素的影响,用离子选择电极连续检测萃取过程中水相Pd(Ⅱ)浓度随时间的变化。实验试剂 N1923中国科学院上海有机化学研究所实验厂生产,经减压蒸馏,收集175-205℃/5-10Torr馏分,电位滴定法分析,每克N1923含3.535mmol伯胺,即平均分子量为283,含量>99.7%。0.200mol·dm~-3N1923的正辛烷溶液 相似文献
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两相滴定法研究2—乙基已基膦酸单2—乙基已基酯从盐酸介质中萃取钕… 总被引:1,自引:0,他引:1
本文利用两相滴定法作为分析手段,用恒界面池搅拌法考察了多种因素对2-乙基已基膦酸单2-乙基已基础从盐酸介质中萃Nd(Ⅱ)动力学的影响,从实验结果推论出萃取过程为界化学反应控制型机理。 相似文献
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叔铵盐—烷烃—醇—水四元体系的热力学函数与结构研究 总被引:5,自引:0,他引:5
叔铵类(R_3N)萃取剂萃取金属离子需在酸性介质中进行,与无机酸先形成铵盐(属阴离子表面活性剂类),然后与金属配阴离子进行阴离子交换反应。而将R_3N制成无机酸盐,作为表面活性剂以微乳液为模型对其进行热力学函数与结构研究尚未见报道。 本文制备了TOA·HCl、N235·HCl、N235·HNO_3与N235·HClO_44种叔铵无机酸盐,测定了叔铵盐的界面化学性质。以w/o型微乳液的球形颗粒结构为模型,用稀释法测定了叔铵盐(TOA·HCl,N235·HCl,N235·HNO_3,N235·HClO_4)-烷烃-醇-水四元均相透明体系的结构参数;并用不同醇时,醇由油相(o)转移至界面层(i)的标准自由能变(?)结果表明其结构“颗粒”半径小于0.5nm,表面活性剂叔铵盐的平均聚集数小于0.05,应属醇的反向胶团。 1 实验 1.1 试剂 三正辛胺(TOA,德国);N235(R_3N,R=C_5—C_(10),大连油脂化学厂)。叔铵盐TOA·HCl分别用干法(D)与湿法(W)制备。向TOA中通入干燥HCl气体至饱和,再加入分析量的TOA中和过量的HCl,制得TOA·HCl(D).TOA与过量10mol/L盐酸振荡平衡,再加入分析量的TOA中和过量酸制得TOA·HCl(W),样品均为淡黄色蜡状固体,N235·HCl、N235·HNO_3、N235·HClO_4均用湿法制备。其它试剂均为A.R.级,未进一步处理,水为二次蒸馏水。 相似文献
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本要用恒界面池法研究了诸因素对甲基膦酸二甲庚酯(P350)从硝酸体系中萃取Nd(Ⅲ)动力学的影响,求得反应的表观活化能为11.8kJ/mol,从实验结果推论出萃取过程为界面化学反应的控制机理,进出萃取反应速率方程,并提出中性磷氧萃取剂在萃取金属离子过程中可能存在阳离子交换反应机理。 相似文献
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钯的萃取化学研究(Ⅱ)——N_(263)萃取Pd(Ⅱ)的动力学研究 总被引:3,自引:0,他引:3
采用离子选择电极作为分析手段,用恒界面搅拌法考察了多种因素对季铵盐N_(263)-正辛烷由氯化物介质中萃取钯(Ⅱ)动力学的影响,从实验结果推论出萃取过程为界面化学反应控制型机理。对酸度、添加剂的影响也作了讨论。 相似文献
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磷酸体系中微量稀土元素萃取动力学研究 总被引:2,自引:0,他引:2
采用新型恒界面池法进行了磷酸体系中用P204萃取La(Ⅲ),Sm(Ⅲ)和Y(Ⅲ)的动力学研究,考察了搅拌速度、温度、比界面积、磷酸浓度及萃取剂浓度等因素对萃取速率的影响.结果表明:磷酸体系中用P204萃取La(Ⅲ),Sm(Ⅲ)和Y(Ⅲ)的表观活化能E_a分别为27.0,22.2和21.1 kJ·mol~(-1),在体相P204浓度大于在液一液界面饱和吸附时的最低浓度C_(min)时,其在界面已达到吸附饱和,反应的主通道由界面变为体相,在该体系下P204萃取La(Ⅲ),Sm(Ⅲ)和Y(Ⅲ)反应为体相化学反应和扩散反应混合控制. 相似文献
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IntroductionItiswellknownthatyttriumcanbeusedinmanyfields ,suchasmetallurgy ,ceramics ,lasersandelectron ics ,especiallyinfluorescentmaterialswhoseneedforhighpurityyttriumoxideisincreasing .InChina ,there sourceofyttriumisrich ,andthehighpureyttriumisbe ingo… 相似文献
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V. Thorn B. Gutierrez C. Pazos J. Coca 《Journal of Dispersion Science and Technology》2013,34(4):407-431
Extraction rates of lactic acid from aqueous solutions using Alamine 336 dissolved in toluene have been studied by the single drop technique. Interfacial tensions as a function of extractant concentration and initial extraction rates as a function of lactic acid and Alamine 336 concentrations are repotted. Assuming the extraction takes place by an interfacial reaction mechanism, a mass transfer model is proposed for lactic acid reactive extraction. The model assumes a mixed regime, in which the slow diffusion transport of the amine extractant to die inner drop interface, and its protonation at the interface are the rate controlling steps. The influence of a synthetic anionic surfactant, sodium n-dodecyl sulphate, on the extraction process has been also studied. For surfactant concentrations above the specific CMC (critical micelle concentration), the surfactant increases the overall mass-transfer rate up to 40%. The surfactant influence on the extraction kinetics is described on the basis of increasing the interfacial potential and the resulting rise of the proton concentration at the interface. 相似文献
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Yunlong Fan Rongji Dai Xuejun Guan Shuyu Lu Chunhua Yang Xuefei Lv Xiaoqiong Li 《Journal of separation science》2023,46(6):2200801
The continuous expansion of nucleic acid detection applications has resulted in constant developments in rapid, low-consumption, and highly automated nucleic acid extraction methods. Nucleic acid extraction using magnetic beads across an immiscible phase interface offers significant simplification and parallelization potential. The gas–liquid immiscible phase valve eliminates the requirement for complicated cassettes and is suitable for automation applications. By analyzing the process of magnetic beads crossing the gas-liquid interface, we utilized a low magnetic field strength to drive large magnetic bead packages to cross the gas-liquid interface, providing a solution of high magnetic bead recovery rate for solid-phase extraction with a low-surfactant system based on gas-liquid immiscible phase valve. The recovery rate of magnetic beads was further improved to 90%–95% and the carryover of the reagents was below 1%. Consequently, a chip and an automatic system were developed to verify the applicability of this method for nucleic acid extraction. The Hepatitis B virus serum standard was used for the extraction test. The extraction of four samples was performed within 7 minutes, with nucleic acid recovery maintained above 80% and good purity. Thus, through analysis and experiments, a fast, highly automated, and low-consumption nucleic acid recovery method was proposed in this study. 相似文献
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The transport of polyamines through the liquid membranes with di-2-ethylhexyl phosphoric acid (D2EHPA) was investigated. The study was performed in three main steps: liquid-liquid extraction (LLE), bulk liquid membrane (BLM) extraction, and supported liquid membrane (SLM) extraction. Equilibrium distribution experiments allowed determining the extraction constants and stoichiometric coefficients for each polyamine. It turned out that one amino group binds two molecules of carrier (one D2EHPA dimer) and the extractability of polyamine rises with the increase in number of function groups in the molecule. The BLM and SLM experiments showed that despite considerable differences in distribution ratio between various polyamines the extraction efficiencies for all of them are very approximate. The smaller diamines compensate the lowest affinity to membrane phase with faster interface reaction kinetics and higher diffusivity. Finally, the SLM extraction conditions were optimized. The main parameters that influence the transport are the pH of the donor and acceptor phases. The extraction efficiencies obtained for polyamines are high (80-90%) and give hope for an application in bioanalytical chemistry. 相似文献
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Véronique Pignon Roger Jeannot Emmanuel Sauvard 《International journal of environmental analytical chemistry》2013,93(4):345-366
Abstract The coupling between liquid chromatography and mass spectrometry with an APCI or ESI interface (in positive or negative mode) is used here for multi-residue analyses in natural waters, covering basic and neutral pesticides as well as acid pesticides. The methods developed are applied to drinking and, river waters after the samples are concentrated by liquid-liquid extraction or solid phase extraction on C18 cartridges. Comparisons are made between UV detection and mass spectrometry and between two chromatographic methods for acid substances. The quantitation limits range from 0.01 to 0.1 μg/l according to the substance. 相似文献
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在(30±0.5)℃下,用层流恒界面池研究了铒在HBTMPTP-正庚烷-0.2mol/L(H,Na)Ac萃取体系中的传质动力学.测定了该体系的界面张力,考察了水相酸度、萃取剂浓度、氯离子浓度、温度和比界面对萃取速率的影响.实验表明,在本实验条件下,萃取过程属于扩散控制过程.Cyanex302中的杂质具有动力学的协萃作用. 相似文献